Fig. 5. The effects of Ca²⁺ concentration on the dominance of the activity of cis and trans axonemes. (A,B) Superimposed frames from video records and associated interpretations of rotating wild-type cells. Cells tended to rotate with the eyespot pointing inwards in a solution containing 10^-6 M Ca²⁺ (A) and outwards in Ca²⁺-free solution (B). Scale bar, 10 µm. (C) The proportion of reactivated cell models whose trans axoneme beats dominantly at various Ca²⁺ concentrations. Each point shows the average and standard deviation from six experiments on wild-type (squares), lsp1 (circles), ptx1 (triangles) and ida1 (crosses) cells. The number of cells counted in each experiment was 29-159.